[USER] Init libc with arguments and environment

MESS - execve - Clean up and move earlier

init/init.c

@@ -4,7 +4,6 @@ int main(int argc, char **argv)
 {
   (void) argc;
   (void) argv;
-  fork();
   for(;;);
   return 0;
 }

kernel/boot/kmain.c

@@ -12,6 +12,7 @@
 #include <syscall.h>
 #include <cpuid.h>
 
+int kernel_execve(process_t *p, void *image, char *argv[], char *envp[]);
 int kmain(uint64_t multiboot_magic, void *multiboot_data)
 {
   debug_init();
@@ -29,12 +30,13 @@ int kmain(uint64_t multiboot_magic, void *multiboot_data)
   debug_info("Syscall enabled:%d\n", CPUID_FEATURE_SYSCALL);
 
   process_t *p1 = process_spawn(0);
-  thread_t *th = exec_elf(p1, mboot_data.init);
+  char *args[] = {"init", "Hello, arg", "5", 0};
+  char *env[] = {"OS=mittos64", 0};
+  thread_t *th = exec_elf(p1, mboot_data.init, args, env);
   scheduler_insert(th);
 
   procmm_print_map(p1->mmap);
 
-
   asm("sti");
   debug_info("BOOT COMPLETE\n");
   schedule();

kernel/include/elf.h

@@ -4,4 +4,4 @@
 #include <thread.h>
 
 void *load_elf(process_t *p, void *data);
-thread_t *exec_elf(process_t *p, void *image);
+thread_t *exec_elf(process_t *p, void *image, char *argv[], char *envp[]);

kernel/include/process.h

@@ -62,5 +62,5 @@ void procmm_free_map(process_t *proc);
 void procmm_print_map(procmm_mmap_t *map);
 procmm_area_t *procmm_map(procmm_mmap_t *map, uintptr_t start, uintptr_t end, uint64_t flags);
 void procmm_unmap(procmm_area_t *a);
-uintptr_t procmm_setup(process_t *proc);
+int procmm_setup(process_t *proc, size_t brk_size);
 registers_t *procmm_page_fault(registers_t *r);

kernel/proc/exec_elf.c

@@ -1,14 +1,80 @@
 #include <elf.h>
 #include <stdint.h>
 #include <debug.h>
+#include <mem.h>
+#include <string.h>
+#include <process.h>
 
-thread_t *exec_elf(process_t *p, void *image)
+thread_t *exec_elf(process_t *p, void *image, char *argv[], char *envp[])
 {
+  int argc = 0, envc=0;
+  // Count strings and save their lengths
+  int len = 0;
+  while(argv[argc]){
+    len += strlen(argv[argc]) + 1;
+    argc++;
+  }
+  len += (argc+1)*sizeof(char *);
+  while(envp[envc])
+  {
+    len += strlen(envp[envc]) + 1;
+    envc++;
+  }
+  len += (envc+1)*sizeof(char *);
+  len += sizeof(size_t)*2;
+  len += sizeof(char);
+
+  // Replace process memory space with new image
   void *entry = load_elf(p, image);
-  debug("Address:%x\n", entry);
-  procmm_setup(p);
+  procmm_setup(p, len);
+
+  // We will write to process memory, so let's switch to it
+  vmm_set_P4(p->mmap->P4);
+
+
+  // Memory layout of area before BRK
+  // argv[]
+  // 0
+  // envp[]
+  // 0
+  // auxv[]
+  // arguments
+  // env strings
+  // 0
+  // BRK points here
+  void *pos = (void *)p->mmap->brk->start;
+  char **_argv = pos;
+  pos = incptr(pos, (argc+1)*sizeof(char *));
+  char **_envp = pos;
+  pos = incptr(pos, (envc+1)*sizeof(char *));
+  size_t *_auxv = pos;
+  pos = incptr(pos, sizeof(size_t)*2);
+
+  // Copy arguments
+  for(int i = 0; i < argc; i++)
+  {
+    size_t len = strlen(argv[i]) + 1;
+    _argv[i] = pos;
+    memcpy(_argv[i], argv[i], len);
+    pos = incptr(pos, len);
+  }
+  _argv[argc] = 0;
+  // Copy environment strings
+  for(int i = 0; i < envc; i++)
+  {
+    size_t len = strlen(envp[i]) + 1;
+    _envp[i] = pos;
+    memcpy(_envp[i], envp[i], len);
+    pos = incptr(pos, len);
+  }
+  _envp[envc] = 0;
+  // No auxiliary vectors for now
+  _auxv[0] = 0;
+
   thread_t *th = new_thread((void *)entry, 1);
   process_attach(p, th);
+  th->r.rsi = (uint64_t)_argv;
+  th->r.rdi = argc;
 
   return th;
 }

kernel/proc/procmm.c

@@ -103,13 +103,13 @@ void procmm_unmap(procmm_area_t *a)
   kfree(a);
 }
 
-uintptr_t procmm_setup(process_t *proc)
+int procmm_setup(process_t *proc, size_t brk_size)
 {
   procmm_mmap_t *map = proc->mmap;
   procmm_area_t *last_a = map->areas.prev;
 
   uintptr_t brk_start = (last_a->end + PAGE_SIZE) & ~(PAGE_SIZE-1);
-  map->brk = procmm_map(map, brk_start, brk_start, 0);
+  map->brk = procmm_map(map, brk_start, brk_start + brk_size, 0);
 
   map->stack = procmm_map(map, USERSPACE_TOP, USERSPACE_TOP, 0);
 

libc/crt0.S

@@ -13,10 +13,12 @@
 
   call _init
 
-  pop rdi
   pop rsi
+  pop rdx
+  movabs rax, offset main
+  mov rdi, rax
 
-  call main
+  call __libc_start_main
 
   call _fini
 

libc/syscalls.c

@@ -46,8 +46,3 @@ long __syscall_common(long num, ...)
   while(1);
   return 0;
 }
-
-struct pthread *__pthread_self()
-{
-  return 0;
-}

libc/thread.c

@@ -0,0 +1,21 @@
+#include "syscalls.h"
+
+struct pthread *__pt;
+
+struct pthread *__pthread_self()
+{
+  return __pt;
+}
+
+SYSCALL_DEF(set_thread_area)
+{
+  SYSCALL_INIT(void *, ptr);
+  __pt = ptr;
+  return 0;
+}
+
+SYSCALL_DEF(set_tid_address)
+{
+  SYSCALL_INIT();
+  return 0;
+}